SPIROMETRY: PRACTICAL TIPS

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SPIROMETRYPRACTICAL TIPS

• Philip Harber MD MPH
• UCLA
• pharber_at_ucla.edu
• WESTERN OCCUPATIONAL ENVIRONMENTAL MEDICAL
  ASSOCIATION

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TOPICS

• SPIT (and how it makes tests inaccurate)
• FLOW-VOLUME OR VOLUME-TIME DISPLAY?
• MORE THAN NUMBERS- LOOK AT THE GRAPH!!
• WHAT IS NORMAL?
• PREDICTED vs LOWER LIMIT OF NORMAL
• LONGITUDINAL TESTING (Advanced Topic)

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TOPICS

• SPIT (and how it makes tests inaccurate)
• FLOW-VOLUME OR VOLUME-TIME DISPLAY?
• MORE THAN NUMBERS- LOOK AT THE GRAPH!!
• WHAT IS NORMAL?
• PREDICTED vs LOWER LIMIT OF NORMAL
• LONGITUDINAL TESTING (Advanced Topic)

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SPIROMETER TYPES

• VOLUME Measure volume directly
• FLOW Measure flow, integrate for volume
• PNEUMOTACHOGRAPH
• Measure flow by pressure drop across a screen

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SPIT

• BLOCKS SOME OF THE HOLES ON THE GRID
• PRESSURE DROP IS GREATER
• FALSELY ELEVATES RESULTS

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TOPICS

• SPIT (and how it makes tests inaccurate)
• FLOW-VOLUME OR VOLUME-TIME DISPLAY?
• MORE THAN NUMBERS- LOOK AT THE GRAPH!!
• WHAT IS NORMAL?
• PREDICTED vs LOWER LIMIT OF NORMAL
• LONGITUDINAL TESTING (Advanced Topic)

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VOLUME- TIME
VOLUME
TIME
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FLOW VOLUME LOOPS
FLOW RATE
VOLUME
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FLOW VOLUME LOOPS
EXHALATION

• SHAPE
• QUALITY
• OBSTRUCTION
• FIXED OBSTRUCT
• EXTRATHORACIC
• VOCAL CORD
• DYSFUNCTION

IN TO SPIRO
OUT TO SPIRO
INHALATION
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TOPICS

• SPIT (and how it makes tests inaccurate)
• FLOW-VOLUME OR VOLUME-TIME DISPLAY?
• MORE THAN NUMBERS- LOOK AT THE GRAPH!!
• WHAT IS NORMAL?
• PREDICTED vs LOWER LIMIT OF NORMAL
• LONGITUDINAL TESTING (Advanced Topic)

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GOOD TEST
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TOPICS

• SPIT (and how it makes tests inaccurate)
• FLOW-VOLUME OR VOLUME-TIME DISPLAY?
• MORE THAN NUMBERS- LOOK AT THE GRAPH!!
• WHAT IS NORMAL?
• PREDICTED vs LOWER LIMIT OF NORMAL
• LONGITUDINAL TESTING (Advanced Topic)

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PFT REPORT
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PREDICTED VALUE

• .

LLN
PRED
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RELATION METHOD

• PERCENT PREDICTED (Divide)
• LOWER LIMIT OF NORMAL (Subtract)

FEV1
AGE
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LLN or PREDICTED??

• WHY DOES IT MATTER?
• AMA TABLES USE BOTH.
• HINT LOOK AT FOOTNOTES
• WORKERS COMP USES BOTH
• RESULTS MAY DIFFER

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TOPICS

• SPIT (and how it makes tests inaccurate)
• FLOW-VOLUME OR VOLUME-TIME DISPLAY?
• MORE THAN NUMBERS- LOOK AT THE GRAPH!!
• WHAT IS NORMAL?
• PREDICTED vs LOWER LIMIT OF NORMAL
• LONGITUDINAL TESTING (Advanced Topic)

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LONGITUDINAL TESTING

• TODAY, WE EVALUATE EACH RESULT CROSS-SECTIONALLY
• Is he normal now?
• FUTURE EVALUATE RATE OF CHANGE IN THE PERSON
  OVER TIME.
• IS SHE DECLINING TOO FAST?

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TOPICS

• SPIT (and how it makes tests inaccurate)
• FLOW-VOLUME OR VOLUME-TIME DISPLAY?
• MORE THAN NUMBERS- LOOK AT THE GRAPH!!
• WHAT IS NORMAL?
• PREDICTED vs LOWER LIMIT OF NORMAL
• LONGITUDINAL TESTING (Advanced Topic)

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THANKS